Discussiones Mathematicae - General Algebra and Applications
Discussiones Mathematicae - General Algebra and Applications > 2006 > 26 > 1 > 85-109
Discussiones Mathematicae - General Algebra and Applications > 2013 > 33 > 2 > 211-219
Discussiones Mathematicae - General Algebra and Applications > 2006 > 26 > 1 > 85-109
Discussiones Mathematicae - General Algebra and Applications > 2013 > 33 > 2 > 211-219